<const/arrA=[1,2,3]/>

<for|val, i| of=arrA>
  <div>${i}: ${val}</div>
</for>

<let/arrB=[1,2,3]/>

<for|val, i| of=arrB>
  <div>${i}: ${val}</div>
</for>

<script>
  arrB = [1, 2];
</script>
